Index words located at the end of textbooks are a list of all topics and entities provided to assist readers in finding the location of the text. These are important terms that are often overlooked but are a good collection of domain-specific entities. We utilized easily accessible 5 diverse ebooks related to manufacturing [1]}, digital manufacturing [2]}, manufacturing process [3]} welding technology [4]} and additive manufacturing [5]}, and extracted the index entities mentioned at the end of the book to expand the list of relevant entities. We found about 3500 relevant entities from various books and added those to our vocabulary.
